Microwave Networks
CM 100Base-T System User’s Manual
5/02/05
Page 2-15
Setting Loopback
Set loopback on most circuits using Quiklink–the CM support software (Appendix B).
Some loopbacks require a custom procedure as the individual loopback discussions that
follow outline.
To access QuikLink menus connect a local maintenance terminal to the Local Access port
as Chapter 4 describes.
To initiate local loopbacks without interfering with the on-line traffic, route transmit and
the receive paths through the side not under test. Determine the on-line path using
QuikLink screen (40). Remote loopback occurs on the far-end radio and not the radio
from which the request was initiated. Received traffic at the far-end circuit loops back to
the local radio.
From the QuikLink main menu:
1.
Select <
CONTROL
AND
MAINTENANCE
> (screen 70) and press <Enter>.
2.
Select <
LOOPBACK
/
MONITORING
> (screen 081) and press <Enter>.
3.
Select the screen number for the associated loopback level and press <Enter>.
4.
Select whether you want to test radio A or B (protected configuration).
5.
Complete unique loopback procedures in the follow discussions.
In loopback the access panel MANUAL LED blinks in one-second intervals. In remote
loopback, the LED blinks at both local and remote radios.
Performing RF Local Loopback
RF local loopback isolates waveguide, antenna-feed, or path-related problems. RF
loopback ensures that a terminal works from the data input to the RF waveguide filters.
RF Loopback Note
RF local loopback stops traffic on the path under test. On protected systems, per-
form RF Local Loopback on the off-line radio.
Use the following steps and configuration in Figure 2-9 to perform RF local loopback.
1.
From the QuikLink menu select Path Switching (071) and press <Enter>.
2.
Set the desired TXU and associated RXU online.
3.
Connect TX MON of the TXU under test to RF IN of the associated RXU using the
attenuator pads and low-loss semi-rigid coaxial cable
(PN 8108615-75)
from the termi-
nal accessory kit. Use the attenuator pads as follows:
SP & DHP 1 x 20-dB pad
(PN 2180011-20)
and 1 x 10-dB pad
(PN 2180011-10)
HP 2 x 20-dB pads
4.
Connect LPBK LO OUT on the TXU to LPBK LO IN on the RXU using a coxial cable
(PN 3085571J01)
.
5.
Place the RF Loopback switch on the RXU under test to ON.
6.
On QuikLink, select Reset Statistics (006) and press <Enter>.
7.
Press <Enter> to clear performance counters on radio A, B, or both.
8.
Select Performance Monitoring (item 4), then press <Enter>.
The performance counters should record no errors on the radio under test. Since AGC and
RSL are not accurate in RF loopback modes, DO NOT make adjustments from these
levels.
Summary of Contents for CM7
Page 2: ......
Page 4: ...Page iv 5 04 05 CM7 8 100Base T System User s Manual ...
Page 16: ...Glossary Page xvi CM System Users Manual X Y Z ...
Page 24: ...Microwave Networks CM7 8 100Base T System User s Manual Pagexxiv ...
Page 62: ...Chapter 2 Operation Page 2 18 5 02 05 CM 100Base T System User s Manual ...
Page 64: ...Chapter 3 Module Descriptions Page 3 2 CM7 8 100Base T ...
Page 88: ...Section 3 3 Transmitter Unit Page 3 3 6 CM7 8 System User s Manual ...
Page 96: ...Section 3 5 RF Power Supply Unit Page 3 5 4 CM System User s Manual ...
Page 100: ...Section 3 6 SP Power Supply Unit Page 3 6 4 CM System User s Manual ...
Page 106: ...Section 3 7 Alarm and Control Unit Page 3 7 6 11 18 03 CM 100Base T System User s Manual ...
Page 124: ...Section 3 11 SYNDES Page 3 11 6 CM System User s Manual ...
Page 130: ...Section 3 12 SCU Page 3 12 6 11 18 03 CM 100Base T System User s Manual ...
Page 138: ...Section 3 13 OWU Page 3 13 8 CM System User s Manual ...
Page 150: ...Section 3 15 NMU Page 3 15 6 CM System User s Manual ...
Page 192: ...Chapter 5 Verification Page 5 20 CM System User s Manual ...
Page 194: ...Chapter 6 Maintenance Page 6 2 7 23 03 CM 100Base T System User s Manual ...
Page 224: ...Chapter 6 Maintenance Page 6 32 7 23 03 CM 100Base T System User s Manual ...
Page 226: ...Site Engineering Page 2 CM System User s Manual ...
Page 230: ...Appendix A T I Curves Page A 4 CM7 8 100Base T System User s Manual ...
Page 267: ...Microwave Networks CM System User s Manual PageB 37 ...
Page 268: ...Appendix B QuikLink Page B 38 CM System User s Manual ...
Page 282: ...Appendix D Alarm Codes Page D 6 5 02 05 CM 100Base T System User s Manual ...
Page 290: ...Appendix E Setting Frequency Page E 8 CM7 8 System User s Manual ...
Page 312: ...CM7 8 100Base T System User s Manual Page I 4 Microwave Networks ...